Actually my son has a friend with very little trouble can program a voting machine to make sure everyone votes for a certain person no matter what lever they pull. He demonstrated it for our election board when they were looking to replace our paper ballots where you draw a line to connect the arrows and the machine counts the ballots as they are inserted and keeps track of how many ballots and compare to the voter roles where you had to sign.
any machine can be tampered with - but you need full access to it before the voting, and no oversight when the votes are read off of it. someone is going to notice.
but fraud through provisional and absentee ballots - those are "real votes" that are cast as part of the process, and then have to be "undone" somehow.
Wonderful. You know, it doesn't seem like it would be all that difficult to develop a fool-proof voting process. What gives?